Hydraulically operated clam buckets are generally to Kinshofer on Sep. 20, 1983. This clam bucket includes a U-shaped carrier, two bucket halves, and a hydraulic cylinder. The bucket halves are pivoted upon the carrier such that the hydraulic cylinder may open and close the bucket halves for purposes of engaging material with the bucket. In particular, each bucket half includes a torque tube having specially machined ends for accepting the pivoting points on the carrier. This torque tube is fixed to the bucket halves, supports the bucket halves relative to the carrier, and also transmits the force from the hydraulic cylinder to the bucket halves for purposes of moving the bucket halves relative to each other.
One problem with this arrangement is that the torque tubes are relatively complicated, include numerous parts, and are costly to manufacture. Another problem with this arrangement is that it does not directly transfer the force from the hydraulic cylinder to the digging edges of the bucket halves. Rather, the force from the hydraulic cylinder is transmitted to the torque tubes, then to the sides of the buckets, then through the sides of the buckets, through the back member and to the digging edge of the bucket. This requires that the sides of the buckets be made more rigid and thus, heavier and more costly.
Another problem with the bucket arrangement of the '167 patent is that the pivot pins (13A) which connect the carrier to the bucket halves are difficult to remove once they have been engaged with the torque tube arrangement of the bucket. More specifically, buckets of this type are typically used in relatively harsh environments for digging abrasive materials (e.g., sand, gravel, construction debris) which require that pivot pins be removed periodically and replaced, where associated bushings may also be removed.
U.S. Pat. No. 2,621,428 issued to Billings on Dec. 16, 1952 discloses a hydraulically operated clam bucket, similar to that of the '167 patent. However, the bucket of the '428 patent transfers the force from the hydraulic cylinder to rods (15) engaged with the bucket halves. One problem with the arrangement of the '428 patent is that a bucket built according to this disclosure may have unacceptable deflection and/or fatigue failure at the locations in the bucket halves where the cylinder is connected to bearing members 19 and 20.
Accordingly, it would be advantageous to provide a hydraulic operated clam bucket arrangement which is configured to provide a more satisfactory transmission of force from the hydraulic cylinder to the digging edges of the bucket halves, and also provide an arrangement which facilitates the removal and lubrication of pivot pins and bearings which support bucket halves relative to a bucket half carrier. It would be advantageous to provide the arrangement with a configuration to prevent deflection and fatigue of the bucket halves.
It would also be advantageous to provide a bucket having means for rotating the bucket such that the bucket is more maneuverable. Additionally, it may be useful to modify the bucket such that it is capable of readily handling elongated members such as telephone poles or rail road ties.